Hello to all,
I am reading the Commentariolum petitionis, (The Handbook of Elections) a great little work, probably written by Quintus Cicero, Marcus' brother. He describes all the ropes of an electoral campaign in Rome (great read, anyway). There is a phrase which I find rather difficult to translate. Quintus is talking about sodalitates, kind of associations used for electoral purposes. These were on the edge of legality and in fact were made illegal some years later. Well, Quintus tells that he was actually there when his older brother met the leaders of four sodalitates who pledged to help Marcus Cicero in his election. I give you the whole paragraph:

I find this very hard. I think I would understand it along these lines, though I feel highly lacking in confidence that I am correct. It's often easier, at least, to work from the errors of others rather than one's own blank slate.

"I know, since I was present, what these men's cronies accepted and guaranteed to you while their [sc., the four named individuals'] cases were being entrusted to you"

i.e., as I take it:

the assumed recipient of the advice either acted as counsel on behalf of the named men or possibly he acted as judge (since causam deferre can mean "bring to court", but we then have to account for "ad te", I do not know whether "causam ad te deferre" can mean "bringing a case to court before you as judge", though the notion that corrupt favouritism shown while on the bench might bring rewards at the next stage of the cursus honorum is not completely foreign, I fear, to Republican Rome, so I guess we must preserve it as a possible meaning, unless context or background eliminates it).

I think we have to take the sodales (not the named individuals) as the subject of reciperint and confirmarint, but in this I seem to differ from your approach. But I am otherwise embarrassed by a surplus of nominatives or accusatives.

I take "in" to mean "while", which is perhaps unusual but not impossible.

I think horum must go with causis though (I suppose) it could just be a very loose genitive of respect, sort of "Concerning whom ... I know ", but that seems intolerably loose.